5. Stir into the lamb broth mixture and heat to a simmer, stirring several times. Serve in bowls with the watercress sprinkled on top.

TIP:

If you can't find watercress in your area, substitute fresh chopped mint or parsley. Skim all possible fat off the broth, for lamb fat has a very high congealing temperature (that is, it sets and becomes solid at a high temperature). This is objectionable to most people. If making this soup ahead of time, chill the broth in the refrigerator so you can remove all the fat.